Title: Revision of the Upper Cretaceous ammonite fauna of the Bakony Mountains (Hungary) Author: Ilona Bodrogi, Elena A. Yazykova-Flidlider, Atilla Fogarasi, M. Baldi-Beke Citation style: Bodrogi Ilona, Yazykova-Flidlider Elena A., Fogarasi Atilla, Baldi-Beke M. (2001). Revision of the Upper Cretaceous ammonite fauna of the Bakony Mountains (Hungary). "Acta Geologica Polonica" (2001, vol 51, No. 1, s. 93-99). Acta Geologica Polonica, Vol. 51 (2001), No.1, pp. 93-99 Revision of the Upper Cretaceous ammonite fauna of the Bakony Mountains (Hungary). ILONA BODROGII & ELENA A.YAZYKOVA-FLIDLIDER2 with contributions of ATILLA FOGARASI3 and M. BALDI-BEKE4 I Geological Institute of Hungary, 14 Stefdnia ut., H-1l43 Budapest, Hungwy 2University of Silesia, Bedzinska st,: 60, 41-200 Sosnowiec, Poland. E-mail: [email protected] 3 Eatvos Lorand University, Department of Geology; 4/A Museum krt., H-1088 Budapest, Hungwy. E-mail: [email protected] 4Rdk6czi u. 42, H-2096 Grom, Hungw}' ABSTRACT: BODROGI,1. & YAZYKOVA-FLIDLIDER, E.A. 2001. Revision of the Upper Cretaceous ammonite fauna of the Bakony Mountains (Hungary). Acta Geologica Polonica, 51 (1), 93-99. Warszawa. A revision of the ammonites from the Bakony Mountains (Hungaty) based on collections of the Geological Institute of Hungary (MAFI) in Budapest, revealed the following sequence of faunas. The youngest Campanian ammonites from the South Bakony are three specimens ofPachydiscus (P.)praecolligatus COLLIGNON, 1955 from the Siimeg area; this is a typical Campanian species. Two specimens of former "Lower Maastrichtian Pachydiscus neubergicus (HAUER)" from Haraszt quany have been re-determined as Early Campanian Eupachydiscus levyi (GROSS OUVRE, 1894). The fragmentary specimen of Mortoniceras sp. has been determined as Texanites (Texanites) sp. from the Upper Santonian. Two ammonite zones can be recognised for these sequences: Texanites sp. (Santonian) and Eupachydiscus levyi (Lower Campanian). Keywords: Upper Cretaceous, Santonian, Campanian, Ammonites, Hungary. INTRODUCTION extent of the marine succession is re-evaluated and con­ sidered to be Lower Santonian to Campanian (G. cal­ For nearly twenty years there has been considerable carata Zone), in contrast with the Upper Santonian to debate about the Upper Cretaceous parastratigraphy of Upper Maastrichtian range determined from paly­ the Bakony Mountains, Hungary (Text-fig. 1), based on nomorphs by F. GOCZAN (1973), BONA (in HAAS & al. palynomorphs, foraminifera and nannoplankton (Smo 1984), F. GOCZAN & A. SIEGL-FARKAS (1989) and A. 1980, 1982; F'ELEGYHAzy 1983, 1985; PARTENYI 1986; SIEGL-FARKAS (1983, 1993, 1994). Since the beginning BODROGI 1993, 1995; BODROGI & al. 1995, 1996). of the century (Loczy 1913) until the present day Recent revision of the biostratigraphy of the Upper (HAAS & al. 1984, BERCZI-MAKK & al. 1996), the exis­ Cretaceous of the Bakony Mountains was based on tence of Maastrichtian strata has been inferred from foraminifers and nannoplankton. It has proven that the occurrence of Pachydiscus (P.) neubergicus (HAUER) Maastrichtian formations are absent in the area in the vicinity of Siimeg. These discrepancies point to between Bakonyjak6 and Siimeg. The stratigraphical the need for a revision of the ammonite fauna. 94 ILONA BODROGI & ELENA A.YAZYKOVA-FLIDLIDER SLOVAKIA -Budapest Fig. 1. Geological map (after TAR! 19.95) of the investigated area The sedimentology, stratigraphy and correlation hole is as follows (after HAAs & al. 1984): Ajka Coal of the Upper Cretaceous sequences of the Bakony Formation (101,0 - 162,7 m), ?Coniacian - Lower Mountains, based on the new data from ammonites, Santonian; Jak6 Marl Formation (38,5 - 101,0 m), foraminifers and nannoplankton, have been recently Upper Santonian (Csingervolgy Member, 70,0 - 101,0 published (BODROGI & al. 1997, 1998). We give here m, and Upper Member, 38,5 - 70,0 m); Pol any Marl new data from the Sumeg Sut-22 borehole section Formation (Rendek Member, 13,0 - 38,5 m), Upper (Text-fig. 2) and a revision of the ammonite collec­ Santonian - Lower Campanian. tion. For more detail lithological description of the units All the ammonites were derived from the Rendek see HAAS & al. (1984). The pelitic marine intercalations Member of the Pohiny Marl Formation, with the excep­ in the upper part contain foraminifera (BODROGI 1995, tion of Placenticeras polyopsis (DUJARDIN) that was unpublished) of Late Santonian age. The Rendek derived from the Csingervolgy Member of the J ak6 Member of the Pol any Marl is interpreted as distal Marl. All the ammonites were re-determined (again, gravity mass flow deposits (HAAS 1981, HAAS & al. with the exception of P. polyopsis). 1984, BERCZI-MAKK & al. 1996). SUMEG SUT-22 BOREHOLE SECTION (TEXT-FIG. 2) SYSTEMATIC PALEONTOLOGY This borehole was drilled in the central part of Order Ammonoidea ZITTEL, 1884 the Sumeg Harazt area, near the Harazt and Varosi Suboder Ammonitina HYATT, 1889 quarries (Text-fig. 1). This is the type-section of Jak6 Superfamily Desmocerataceae ZITTEL, 1895 Marl and Ajka Coal Formations in the Sumeg area. Family Pachydiscidae SPATH, 1922 The 149,7 m thick Upper Cretaceous sequences were deposited over the Late Aptian Crinoidea Tata Genus Pachydiscus ZITTEL, 1884 Limestone Formation and are overline by clastics. The lithostratigraphy and subdivision of the bore- TYPE SPECIES: Ammonites neubergicus HAUER (1858, iL.CRETACEOUS UPPER CRETACEOUS TERT. UJ 1 V.APTIAN . CONIACIAN-L.SANTONIAN ----· UPPER SANTONIAN C~ TArA LIMEST. AJKA COAL JAK MARL ~ V.MEMBER ~ ~---.--- --- -- v­ .... v­ 00 C1 3;:3 a :::.8 <3 a v, .... a r:/J C: n ct ~ tv ~ tTl I [/),::;, N ~ S N n (D tTl (Jq 0 [/) c::: s: to Vl N tv 0 ~ oV ~ ~ >-! 0 (D ~ ::r z o ) ::j (; ::r: tTl Vl '"(D 0 tr1 ~ ~ O· ~ 0 , I E ~ I ~ '" I ,t::;1 1t::;1 "0 >-l ~. ) , I. I. '& 0>®~ .'" ...,P> ::r:: S­ '-+ '--+- ~ ~ t v- () tTl O' n P> til P> IJj :;J Cl :;:.C:1 '""';:; () -~ 0 ~ ..., » '-< (l 2 7i S I: { A (l :l P> ~ • ~~ ~ v,P> (l 3 P> 0 S· !f -8.. , '-< P> ::l Z a: '%j - (1) ~ 3 s ~g -< ~ g; ! 0 ~c: P> :1. ..., :;J a: n" '" v-. x_. iJ () "'"~ .3~ !c. 3 _. P> 3 - Sigalia deflaensis 0 '" ....!:. c::: '"0. ~ Vi' - Vidalina hispanica z "c- '<'" "0 '" :t 3 ~ '" ... 0' to - Nummofallotia cretacea '"o 0 Z 'D'" ;;;' Goupillaudina lecontrei "Vl r ::r:: fl o CTIro '8:l ~ Goupillaudina cf. ostrowsky c::: '"~ z o () ",l:;: ." ,» 5 :l.g ",,,--<'" ~ ,:;j - Vaginulina scalariformis ~ '"~ ~ to (D ;;j":t " Nonionella cretacea ~ ::;. '";0 ~ -s () • -"no<> "ti N~ - Cornuspira cretacea '" ~ x" "1j -<~ - Epistomina supracretacea ... " ~ ".., ...:) - Rotalia reicheli ~ is- ~ !l. I~ :·------Dlcarinellac:~~etrica;~-~ ~~~~v. l!- 'Dco 96 ILONA BODROGI & ELENA A.YAZYKOVA-FLIDLIDER p. 12, PI. 2, Figsl-4, by subsequent designation of DE 1938. Eupachydiscus levyi GROSS OUVRE; COLLIGNON, p. 14, GROSSOUVRE, 1894, p. 177). Text-fig. A; PI. 3, Fig. 3. 1955. Eupachydiscus levyi GROSSOUVRE; COLLIGNON, p. 34, Pachydiscus (Pachydiscus) praecolligatus COLLIGNON, Fig. 5. 1955 1977. Eupachydiscus levyi GROSS OUVRE; COLLIGNON, p. 30, PI. (PIs 2-3; PI. 4, Fig. 1) 619, Fig. 2305. 1980. Eupachydiscus levyi GROSSOUVRE; BLASZKlEWICZ, p. 41, 1952. Pachydiscus praecolligatus; COLLIGNON, p. 66, PI. 21, Fig. 1; PI. 31, Figs 1-2. PI. 25, Figs 2-3. 1994. Eupachydiscus levyi (GROSSOUVRE); WIEDMANN in 1955. Pachydiscus praecolligatus; COLLIGNON, p.64, Text-fig.19, GISCHLER & al., p. 236, PI. 43, Figs 8-9. PI. 21, Fig.l; PI. 25, Figs 2-3. 1997. Eupachydiscus levyi (GROSSOUVRE); ATABEKIAN in 1970. Pachydiscus precolligatus COLLIGNON; COLLIGNON, p.40, ARKADEV & al., p. 123, PI. 48, Fig. 4; PI. 49, Figs 1-3. PI. 624, Fig. 2313. 1998. Eupachydiscus levyi (GROSSOUVRE); KENNEDY & JAGT, p. 1994. Pachydiscus (Pachydiscus) precolligatus COLLIGNON; 159, PI. 4, Figs 1-3; PI. 5, Figs 1-3; PI. 6, Figs 3-4 WIEDMANN in GrscHLER & al., p. 234, PI. 43/6, 7; Fig. 16b. HOLOTYPE: Pachydiscus levyi GROSS OUVRE, 1894, p. 178, PI. 21, from Lower Campanian of Carrieres de HOLOTYPE: Designated by COLLIGNON (1952) Contes-Ies-Pins, the Alps. Pachydiscus praecolligatus, p. 66, PI. 21, Fig. 1(= 1955, p. 64, Fig. 19, PI. 21, Fig. 1), Campanian, Madagascar. MATERIAL: The two specimens (K-8645 and S-448) from the Siimeg area, South Bakony, Hungary MATERIAL: Three specimens, K-2728 and S-373 la,b (Museum of the Hungarian Geological Institute - (two examples) from the Siimeg area, South Bakony, MAFI), collected by J. NoszKY. Hungary (Museum of the Hungarian Geological Institute - MAFI), collected by K. PAPP. DESCRIPTION: Both specimens well-preserved inter­ nal moulds. Medium to large size for genus. Semi-invo­ DESCRIPTION: Specimen K-2728 moderately well lute, involution[?] reaching over 70%, moderately com­ preserved internal mould; specimen S 373 Ib worn and pressed. Ventral side rounded. Whorl section oval and corroded; specimen S-373 la fragmentary. Coiling high, higher than wide. Umbilicus comprising estimated moderately involute, involution reaching over 70% in 30-34% of diameter; moderately narrow, shallow, with some specimens; moderately .compressed. Umbilicus a low, steep wall. Ornament consisting of strong, coarse comprising estimated 20-24% of diameter. Ventral side ribs. These pro-sinuos on flanks, primaries starting with rounded. Whorl section broadly rounded to subtriangu­ umbilical tubercle near umbilical edge, 1-3 shorter sec­ lar, higher than wide. Whorl section with small number ondary streams intercalated on flanks, all ribs crossing of blunt ribs and small tubercles. rounded venter with pronounced sinuosity (16 primary ribs corresponding to 36 external ribs per whorl). OCCURRENCE: Campanian of Madagascar; Lower Campanian of Spain; the specimens from Hungary are DISCUSSION: These specimens are similar to the Early Campanian in age (they were collected in Siimeg holotype, which has 14 primary and 36 external ribs per area, South-Bakony). whorl. Genus Eupachydiscus SPATH, 1922 OCCURRENCE: Lower Campanian of Europe, Crimea, Caucasus and Middle Asia; upper Lower TYPE SPECIES: Ammonites isculensis REDTENBACHER, Campanian of Madagascar. The Hungary specimens 1873; WRIGHT, 1957, p. L380. are from the Lower Campanian of the Siimeg area, South-Bakony.